1. Field of the Invention
The present invention relates to a boat propulsion device.
2. Description of the Related Art
A boat propulsion device has been well-known as being equipped with a resin cowling assembly composed of a top cowling and a bottom cowling, and a coupling mechanism for coupling the top cowling and the bottom cowling (see Japan Laid-open Patent Application Publication No. JP-A-H06-40392). The coupling mechanism includes a cam driven portion and a cam block. The cam driven portion is attached to the top cowling, whereas the cam block is attached to the bottom cowling. The bottom cowling includes an attachment block disposed on the inner surface thereof. The attachment block supports the cam block (therefore, the attachment block will be hereinafter referred to as “a support portion”). The support portion is composed of a plurality of plate-shaped members. The plate-shaped members are uniformly formed with a small thickness in order to entirely form a joint section of the support portion to be joined to the bottom cowling with a small thickness. Thus, it is possible to prevent dents attributed to molding shrinkage of the support portion from being produced in the bottom cowling by thinly forming the joint section joined to the bottom cowling.
However, when the support portion is entirely formed with a small thickness, a drawback is created in that the strength of the support portion itself is inevitably degraded.